Positives

• Reduced fatigue and better muscle energy: A six‑month study on post‑COVID fatigue syndrome found creatine (4 g/day) improved tissue bioenergetics and cut fatigue scores by roughly 20 %. PMC

• Cognitive and strength gains in overlapping illness: In a 6‑week magnetic‑resonance study, ME/CFS patients taking creatine showed higher brain phosphocreatine, stronger hand‑grip, and milder mental fatigue—mechanisms thought relevant to Long COVID, too. PubMedPMC

• Anecdotal “game‑changer” reports: Posts on r/covidlonghaulers describe 5–8 g/day restoring workout tolerance and “lifting the brain‑fog cloud” within a month. Reddit

• Clinician endorsements for rehab: Pulmonary‑rehab reviews suggest 5 g/day can safely boost functional recovery after COVID‑19, mirroring COPD data. PMC

• Early expert commentary: University of Nebraska clinicians highlighted three‑month creatine courses that “substantially” eased fatigue and enhanced physical capacity in Long COVID cases. Home

Negatives

• Symptom flare‑ups for some: Several long‑haulers on Reddit reported worse dizziness, brain‑fog, and “about‑to‑pass‑out” feelings after starting 5 g/day, backing off within days. Reddit

• Water retention & GI upset: User threads and supplement reviews note bloating, mild diarrhea, or five‑pound weight gain during loading phases. Verywell Health

• Kidney‑health cautions (low evidence): Case reports raise theoretical risk in those with pre‑existing renal disease, prompting calls for baseline creatinine checks before high‑dose use. PMCPMC

Hurdles & Side Effects

• Sparse Long‑COVID‑specific trials: Only a handful of small, uncontrolled studies exist; larger RCTs are still being designed, so clinicians must extrapolate from ME/CFS and sports data. PubMedPMC

• No agreed dosing protocol: Studies range from 3 g to 8 g/day; without guidelines, patients experiment, risking dehydration if fluid intake is low. PMCReddit

• Product‑quality variability: Over‑the‑counter powders differ in purity; third‑party testing (e.g., NSF Certified for Sport) is advised to avoid contaminants. Verywell Health

• Expectation management: Benefits are gradual (weeks to months) and largely confined to physical stamina; it is not a cure‑all for autonomic or inflammatory symptoms highlighted in Long COVID. HomePMC